One-Way audio on SIP trunk at remote location

[gpatchev]

I have a 3300 setup to do SIP with a local provider. Everything seems to be working well with the exception of ringing another device at a branch location on a different subnet.

If I have the DID resolve to an extension in Head Office it works fine. When I change the DID to ring a set in a branch location I get one-way audio.

I believe that the 5330 set is trying to talk to the IP address of the SIP Peer directly and not bridge the call through the Mitel 3300 controller.

Is there a way to force the call to only use the Mitel 3300 controller?

For example the call comes in on 1.1.1.1 and connects to my Mitel at 2.2.2.2. Mitel on 2.2.2.2 calls extension 3.3.3.3. I don't want 1.1.1.1 to talk to 3.3.3.3 directly. I want the Mitel 3300 at 2.2.2.2 to retain call control.

Any suggestions?

[brantn]

No there isn't a way to do this as it is proxying that you are looking for. Call setup terminates where the trunk terminates. However I would look at Simulated CCM before ISDN progress on the SIP trunks this changes signalling between controllers and fixes many one way audio issues on SIP trunks.

[gpatchev]

Hi brantn,

We have asked the provider to create a route to our remote branch. They did so and everything worked properly.

So can I use a proxy in in the Network Element to get around this issue?

[brantn]

Potentially you would still have to have a medium to route across Mitel IP trunks would have worked fine. With a proxy depending on type you could potentially rewrite the entire header.